Rattlesnake Mountain is a 1,489-foot peak in the Kittatinny Mountains of Sussex County, New Jersey, within the Delaware Water Gap National Recreation Area and along the Appalachian Trail. Near the junction of unmarked Mullins Road and the trail, it takes its name from the broader Kittatinny Ridge's rocky terrain, where rattlesnakes sun themselves. The mountain's significance today lies in its place within a protected recreation landscape and as a notable stop on one of the country's best-known long-distance hiking routes.